Viola tricolor var. hortensis. The classic heirloom Swiss Giants Mix Pansy seeds blend has single colours with blotched faces and some bicolours, with flowers held high above the leaves. Technically a perennial, this plant is usually grown as a cold hardy annual that will bloom in mild climates from October through to May from a late summer sowing. Swiss Giant Pansies grow to about 20cm (8") tall, with a really beautiful range of warm colours and markings that seem to lend the flowers even more personality. This pansy blend works very well in containers and hanging baskets, but the real show is from mass plantings in a flower bed display.
Perennial (Grow as a hardy annual)
This large genus includes both hardy annuals and perennials that are variously known as pansies, violets, Johnny-Jump-Up, and Heartsease. Continue reading below for some tips on how to grow pansies and Violas.
Viola tricolor, V. x wittrockiana, V. odorata
Timing can be tricky, depending on the variety. Johnny Jump-Ups are very easy.
Season & Zone
Exposure: Full sun to partial shade
Start indoors 10-12 weeks before planting out. For spring planting after last frost, that means up to 3 months growing time indoors. Otherwise, sow direct outdoors in summer to early autumn. For winter-flowering pansies in Zones 7-9, start seeds in mid to late June. For V. odorata: Direct sow in autumn or early spring. This variety benefits from a long exposure to cool soil.
Even though the seeds are tiny, they need to be sown 5mm (¼”) deep. Keep the soil at 18-25°C (65-75°F), in complete darkness until they germinate in around 14 days. Then provide bright light to keep plants compact. Space at 15-23cm (6-9″) in the garden. For V. odorata: Barely cover the tiny seeds. Sow in flats sunk into the ground against a north-facing wall, and cover with glass or plastic. Remove cover when seedlings emerge. Germination can take up to 50 days, so be patient.
After germination, violas are easy. Fertilize once or twice in early growth and provide a mulch around plants to keep roots cool as weather warms. Deadhead to prevent self-sowing, particularly with Johnny-Jump-Ups.
For V. odorata: Transplant after last frost or in the autumn where winters are mild, spacing at 15-30cm (6-12”) apart. Grow in partial shade, or in full sun where summers are cool. This variety prefers rich, moist, well-drained soil with a pH of 5.5-7.0. Add well-rotted manure at transplant time.